Shaving implement



Jly 13, 1937.

JL F. KOEHLER SHAVING IMPLEMENT Filed Sept. 30, 1935 Patented July .13,1937 i 2,085,715

UNITED STATES PATENT OFFICE snAvrNG IMPLEMENT James Frederic Koehler,Northampton, Mass. Application September 30, 1935, Serial No. 42,853 4Claims. (Cl. 31o-43) This invention relates to an improved shavingtached to the base plate 4. The base plate 4 is implement which iseasily manipulated and which attached to the handle i by screws or othersuitis used to secure a close shave with rapidity and able means, and apost 5 is made a rigid part of safety. The machine does not require theuse of the base plate. The post 5 carries the cutting 5 lather. blade 6,which blade is replaceable when neces- 5 'Ihe invention comprises animplement ln sary, and is firmly held on the somewhat enwhich asharpened blade rests flatly against the larged outer end of the post bythe clamping plate skin, the cutting edge being immediately adjacent 1which is drawn tightly against the blade and to the skin, and a rotatingslotted cylinder beats the post by the screws 8. The clamping surfacethe hairs against the cutting edge. The slots in of the post and theinner surface of the clamping 10 the cylinder are sufficiently narrow sothat the plate are shaped to ilrmly hold the cutting blade skin cannotenter them, and is therefore preventin such a position that its cuttingedge 9 is the ed from beingy cut by the keen edge. only part of theblade in contact with the rotating This form of machine provides a veryclose cylinder 2. The outer surface of the clamping shave, for by thedisposition of the cutting edge, plate 1 presents a smooth surface tothe skin. 15 the hairs are cut off iiush with the skin. The The contactline 9 of the cutting blade B and rotating cylinder presents only asmall arc of its the curved face of the rotating cylinder 2 is1ocircumference to the skin, the blade edge touchcated almost upon, orslightly to the rear of the ing the cylinder but slightly to the rear ofthe line of tangency made by the Skin upon the cylinpoint or tangenoywith the skin, and a guard beder, and the two lines are parallel. Whenprop'- 20 lng brought around the cylinder on the opposite erly set for aCIOS@ Shave, the Cutting edge 1S not side almost into contact with thistangent plane. more than ten one-thousandths of an inch behind The smallarea of contact which the cylinder the tangent line, as measured alongthe direction makes with the skin, together with the small of the skinsurface, so that the hairs are severed speed of rotation and the smalldiameter of the almost exactly at the surface of the skin. It hascylinder, act to cause practically no discomfiture also been found thatwhen so adjusted the Cutasl the cylinder moves over the skin. Nor arethe ting blade 6 shows no tendency to dig into the narrow slots in thecylinder uncomfortable to the hard, smooth cylindrical surface. skin.The entire instrument can be easily and The rotating cylinder isprovided with slots Ill safely moved about on the surface of the skin.into'which the hairs may project, and the rota- 30 The invention alsocomprises various details tion of the cylinder is directed to bring thehairs of the construction which details will be more against the cuttingedge. The slots are cut nar-A fully set forth hereinafter and will alsobe emrow so that the skin cannot enter them, and the bodied in theclaims. cylindrical surface therefore acts as a guard to 3,5 Theinvention is illustrated in the accompanyprevent the skin being broughtagainst the cuting drawing in which Figure 1 is a front view of a tingedge and injured. The most emcient arshaving implement embodying myinvention. rangement of slots seems tov be the herring-bone Figure 2 isa side View of the same. Figure 3 is pattern, which is easy toconstruct, and is illusan end view of 'the shaving head only and omitstrated in the drawing. 1t comprises several series- 49 details of thebase and handle. 1n Figure 3is also of slots lo, each series being sawedor milled or 40' shown a method for attaching a guard about the groundalong a part of the curved face of the rotating cylinder, which guardhas been omitted cylinder, all slots of one series being in plane fromall other' figures for the sake of showing delaminae which constitute aparallel set. Any tail. Figure 4 is an enlarged section of the shavslotin one series is of such depth that it cuts ing head taken on the lineiiii3 in Figures 1 through all generating lines lying within a 45 and 2.Figure 5 is a perspective view of a vportion quarter (or a sixth or aneighth) of the surface o of the rotating cylinder. the cylinder; thenext series cuts through all The machine comprises ahandle l which fitsgenerating lines withinthe adjacent quarter (or the hand and containssome appropriate source sixth or eighth) of the surface and in this way50 of power, such as an electric motor, or the end of iour (or six oreight) series are out around the 5g a idexible4 shaft. From the handleprojects a rocylinder. The common angle between the cylintating cylinder2, attached to the source of power. der axis and any one series ofparallel 'laminae No further bearings for this cylinder are requiredcontaining a given series of slots is alternately beyond those centeringthe source of power. A given an acute or an obise value in progressingbearing may be incorporated in the collar 3 atfrom one series to the adacent sexies around the` 55 curved surface of the cylinder. Particularvalues of 45 degrees and 135 degrees are illustrated in the drawing, butit is understood that other values of these angles may be used as well.The alternating directions serve in a semi-oscillatory manner tobring-the hairs to the cutting edge from both side directions as well asfrom the front of the edge. This pattern of construction of slotson thecylinder surface will be referred to in the claims as the herring-bonepattern.

'I'he remaining surface of the cylinder is highly polished to slideeasily over the skin. The diameter of the cylinder may be as small as isconsistent with the bending strength of the material used. A smalldiameter is desirable to reduce unnecessary friction with that part ofthe skin not adjacent to the cutting edge. A diameter of aboutone-quarter of an inch has been found to be satisfactory. The length ofthe cylinder depends on the amount of clearance required by the sourceof powerin the handle to permit convenient manipulation of theimplementv over the skin, and need not exceed three inches.

A guard Il as shown in Figure 3, or other suitable arrangements may befitted about the rotating cylinder Ato prevent parts of the cylinder notadjacent to the cutting edge from touching the skin and causingunnecessary friction. Holes I2 in'this guard permit the cut hairs to bethrown free.

A modification of this implement consists in having two blades, one oneach side of the rotating cylinder, and a reversible source of power,

so that the operator may Acause the hairs to be brought against eitherblade at will, and may v place that blade against the skin for shaving.The rotating cylinder herein described will serve this double purpose.

'I'he shaving implement described will shave surfaces bearing eitherlong or short hairs, and will shave closely. The novel feature of theinvention is the ability of the implement to shave closely, and thatWithout the aid of lather. That type of lather-less shaving implementwhich employs a shearing plate, or shearing plates, cannot cut the hairsshorter than the thickness of the shearing plate. In the implementherein described the cutting takes place exactly lon the surface of theskin. And whereas other types of implements employing keen blades willalso cut on the skin surface, they require the use of lather to holdthehairs erect, while the latter purpose is herein accomplished by therotating cylinder. Moreover the implement herein described offers a muchbetter protection to the skin against accidental cutting by thesharpened edge than is found in most other shaving implements using asharpened cutting edge. A further novelty in the herring-bone pattern ofthe slots on the cylinder lies in the accomplishment of an oscillatoryeffect through the more efflcient means of a rotation.r

It Will also be seen that the disposition of the slots in parallellaminae in the rotating cylinder permits of a rapid and inexpensiveconstruction of these cylinders by multiple arrangements of saws,milling cutters, or grinding disks, and allows the use of hardenedmaterials.

It will be understood that modifications can be made in the dispositionof the cutting slots within the parallel laminae on the rotatingcylinder, and also in the construction. arrangement and combination ofthe various parts of this shaving implement, Without departing from thescope and principle of my invention.

I claim: i

1. A shaving implement comprising a cutting edge to rest against theskin, a slotted cylinder rotating about its axis to bring the hairsagainst the cutting edge, where they are severed, the slots being cut ina herring-bone pattern on the surface of the cylinder and being narrowto prevent the skin from entering them and being injured at the cuttingedge, with means for rotating the cylinder and for holding the cuttingedge firmly against the cylinder surface.

2. A shaving instrument comprising a very thin shearing plate to restagainst the skin, a slotted cylinder rotating about its axis to bringthe hairs against the cutting edge, where they are severed, the slotsbeing cut in the cylinder surface so that all parts of any finite lengthof one slot lie in a plane lamina of thickness equal to the slot width,the slot width being narrow to prevent the skin from entering and beinginjured at the shearing edge, with means forrotating the cylinder andfor holding the shearing plate firmly against the cylinder surface.

3. A shaving instrument comprising a sharpened cutting edge to restagainst the skin and to bear on a rotating slotted cylinder which bringsthe hairs against the cutting edge, the slots being cut in the cylindersurface so that .all parts of any finite length of one slot lie in a.plane lamina of thickness equal to the slot' width, the slot width beingnarrow to prevent the skin from entering and being injured at thecutting edge. with means for rotating the cylinder and for holding theshearing plate firmly against the` cylinder surface.

4:. An implement for shaving, comprising a handle incorporating a sourceof power, a shaving head on the end of the handle to hold a blade whosesharpened cutting edge rests against 'the skin, a rotating cylinderattached to the Ithe head to surround the cylinder except in immediateproximity to the cutting edge.

JAMES r.y KOEHLER.

